Until the 20th century, up to 73% of human mortality could be attributed to infections. (See, e.g., Crimmins, E. M., and C. E. Finch. 2006. Infection, inflammation, height, and longevity. Proceedings of the National Academy of Sciences of the United States of America 103:498-503.) Recognition of the germ theory of disease led to increased sanitation and the development of antimicrobial therapies, which reduced this limitation on human longevity. While the chances that one will die from an infection or infectious disease is small compared to previous centuries, within the hospital setting, the chances of acquiring a possibly fatal infection continues to rise. (See e.g, Scott, R. D. 2009. The direct medical costs of healthcare associated infections in US hospitals and the benefits of prevention. Centers for Disease Control and Prevention.) The extensive use of antibiotics, although revolutionary and effective, has nonetheless resulted in acquisition of resistance genes by hospital strains of organisms, making nosocomial infections increasingly hard to treat. A recent estimate states that 1.7 million such infections occur annually with a death toll of 100,000 people per year and a direct cost of $45 billion dollars.
Bacteria attached to solid surfaces can form a major reservoir for pathogenic organisms. In addition, attached cells can rapidly form biofilms, which are not only more resistant to disinfection than single or planktonic bacteria, but also demonstrate increased genetic exchange. Accompanied by selective pressure from the myriad of antibiotics and disinfectants used within the hospital setting, lateral genetic exchange, which occurs even between genera, can result in the formation of multiply resistant organisms. According to the recent reports, multiply resistant bacteria are responsible for 16% of hospital acquired infections. (See e.g., Hidron, A. I., J. R. Edwards, and J. Patel. 2009. Antimicrobial-resistant pathogens associated with healthcare-associated infections: annual summary of data reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2006-2007 (vol 29, pg 996, 2008). Infection Control and Hospital Epidemiology 30:-. and Seigal, J., E. Rhinehart, M. Jackson, and L. Chiarello. 2006. Management of multi-drug resistant organisms in healthcare settings, 2006. Centers for Disease Control and Prevention.)
Infection control has, thus, become a major focus of modern hospital infection management. Isolation of infected patients, the use of gowns and gloves by healthcare personnel, frequent handwashing and assiduous cleaning of hard surfaces have all been shown to be effective in controlling even the most resistant pathogens. Only recently have hospital textiles been considered an important reservoir for pathogens; a recent mathematical model predicts that organisms attached to textiles can contaminate both health care workers' hands and room air. (See, e.g, Nicas, M., and G. Sun. 2006. An integrated model of infection risk in a health-care environment. Risk Analysis 26:1085-1096.) This model has been verified in a meta-analysis on the transfer of multiply resistant organism colonization patient beds demonstrated that not only bedlinens, but pillows, mattresses and even fire blankets under mattresses may be a reservoir for infection, with transfer of the organisms to the air and hands occurring during bedmaking. (See e.g., Creamer, E., and H. Humphreys. 2008. The contribution of beds to healthcare-associated infection: the importance of adequate decontamination. Journal of Hospital Infection 69:8-23.) One effective strategy for preventing the airborne spread of infection is the judicious use of curtains, (Ching, W. H., M. K. H. Leung, D. Y. C. Leung, Y. Li, and P. L. Yuen. 2008. Reducing risk of airborne transmitted infection in hospitals by use of hospital curtains. Indoor and Built Environment 17:252-259.) but, these, too, may serve as a reservoir for pathogens, including drug resistant strains. (Klakus, J., N. L. Vaughan, and T. C. Boswell. 2008. Meticillin-resistant Staphylococcus aureus contamination of hospital curtains. Journal of Hospital Infection 68:189-190. and Trillis, F., E. C. Eckstein, R. Budavich, M. J. Pultz, and C. J. Donskey. 2008. Contamination of Hospital Curtains With Healthcare-Associated Pathogens. Infection Control and Hospital Epidemiology 29:1074-1076.) Such concerns are not limited to the hospital setting; household shower curtain biofilms can be a major reservoir for opportunistic pathogens. (Kelley, S. T., U. Theisen, L. T. Angenent, A. S. Amand, and N. R. Pace. 2004. Molecular analysis of shower curtain biofilm microbes. Applied and Environmental Microbiology 70:4187-4192.) Release of attached pathogens is thus, undesirable, and a truly effective biocidal fabric would both retain and kill attached organisms.
A recent review (Gao, Y., and R. Cranston. 2008. Recent advances in antimicrobial treatment of textiles. Textile Research Journal 78:68-72) has explored different antimicrobial textiles. These include not only those used in healthcare settings, but also those used to enhance personal hygiene and prevent deterioration of fabric. Among the most effective strategies are those using heavy metals and their salts, quaternary ammonium, polyhexamethylene biguanides, trichlosan, N-halamine compounds, and peroxyacids. While all are effective, all have substantial drawbacks, including the need for regeneration (N-halamines, peroxyacids), low biocidal activity (trichlosan, PHMB), toxic by products (trichlosan) and development of resistant strains
Accordingly, there is a substantial need for new methods for providing antimicrobial protection to textiles and novel textiles having antimicrobial properties.